Engineering NiO/NiFe LDH Intersection to Bypass Scaling Relationship for Oxygen Evolution Reaction via Dynamic Tridimensional Adsorption of Intermediates.

Oxygen evolution reaction (OER) is a pivotal reaction in many technologies for renewable energy, such as water splitting, metal-air batteries, and regenerative fuel cells. However, this reaction is known to be kinetically sluggish and proceeds at rather high overpotential due to the universal scaling relationship, namely, the adsorption energies of intermediates are linearly correlated and cannot be optimized simultaneously. Several approaches have been proposed to break the scaling relationship by introducing additional active sites; however, positive experimental results are still absent. Herein, a different solution is suggested on the basis of dynamic tridimensional adsorption of the OER intermediates at NiO/NiFe layered double hydroxide intersection, by which the adsorption energy of each intermediate can be adjusted independently, so as to bypass the scaling relationship and achieve high catalytic performance. Experimentally, the OER overpotential is reduced to ≈205 mV at current density of 30 mA cm-2 , which represents the best performance achieved by state-of-the-art OER catalysts.